1. To make the dough, place 2 cups flour, 1 teaspoon salt, and the granulated sugar in a food processor and pulse to combine. Add the cream cheese and butter and pulse until the fats are incorporated but the mixture still looks rough and pebbly.
2. Whisk together 1 egg and the milk in a small bowl. Pour this down the feed tube of the food processor, then pulse just until the dough comes together in a big clump.
3. Generously flour the work surface. Dump out the dough onto the surface and form it with your hands into a rectangle about 8 by 6 inches. Wrap the dough tightly in plastic wrap and refrigerate it until firm, at least 1 hour, up to 1 day.
4. When you’re ready to assemble the tarts, unwrap the dough (reserve the plastic) and cut it in half widthwise to form two rectangles of equal size. Rewrap one rectangle and refrigerate it while you work with the other.
5. Place a large piece of parchment paper on the work surface. Generously flour it and a rolling pin. Place the dough in the center of the parchment and roll it into a 12-by-9-inch rectangle about 1/8-inch thick. Use a ruler and sharp knife to trim the dough if you need to. Transfer the dough, on its parchment, to the fridge to chill.
6. Roll out the second piece of dough in exactly the same way. You’ll end up with two 12-by-9-inch sheets of dough. Chill both to firm up, at least 10 minutes.
7. Use a sharp knife to cut each sheet of dough in half lengthwise, then in quarters widthwise; you’ll end up with eight 3-by-41⁄2-inch rectangles per sheet (16 total). Return the rectangles of dough, still on their parchment sheets, to the refrigerator while you mix up the filling.
8. To make the filling, whisk the remaining 4 teaspoons flour, the brown sugar, and the cinnamon in a small bowl until well combined. 
9. Flour a clean work surface and line up the chilled dough rectangles on it in two rows. Beat the remaining egg in a small bowl. Brush some over half the rectangles. These are the bottoms, and the egg will help the filling and tops to stick. Refrigerate the remaining egg, along with the brush.
10. Prick the other rectangles a few times with a fork. These will be the tops (pricking them will help vent the steam in the oven).
11. Spoon a heaping tablespoon of filling in the center of each bottom rectangle, leaving a 1⁄4-inch border around the edges. Carefully place a top rectangle over each bottom and press the edges together with your finger to seal. Ensure an even seal by pressing the tines of a well- floured fork around the edges of each tart.
12. Line a sheet pan with parchment paper. Use a spatula to gently transfer the tarts to the prepared pan, spacing them evenly apart. Refrigerate the tarts, uncovered, one last time for 15 to 30 minutes.
13. While the tarts are chilling, preheat the oven to 350°F with a rack in the center position.
14. Brush the tops of the tarts lightly with the remaining beaten egg. Bake the tarts until deeply golden brown, 20 to 25 minutes.
15. While the tarts are baking, make the glaze: Whisk the confectioners’ sugar, a pinch of salt, and the maple syrup in a small bowl until smooth.
16. Let the tarts cool slightly, then drizzle the maple glaze over them before serving.

Extra tarts can be wrapped tightly in plastic wrap and stored at room temperature for 2 to 3 days, or in the freezer for up to 3 months.